Lee C C, Kohara Y, Akiyama K, Smith C L, Craigen W J, Caskey C T
Institute for Molecular Genetics, Baylor College of Medicine, Houston, Texas 77030.
J Bacteriol. 1988 Oct;170(10):4537-41. doi: 10.1128/jb.170.10.4537-4541.1988.
The termination of protein synthesis in Escherichia coli requires two codon-specific factors termed RF1 and RF2. RF1 mediates UAA- and UAG-directed termination, while RF2 mediates UAA- and UGA-directed termination. The genes encoding these factors have been isolated and sequenced, and RF2 was found to be encoded in two separate reading frames. The map position of RF1 has been reported as 27 min on the E. coli chromosome, while the RF2 map position has not yet been identified. In this study, two new and independent methods for gene mapping, using pulsed field gel electrophoresis and an ordered bacteriophage library spanning the entire chromosome, were used to localize the map position of the RF2 gene. In addition, the location of the RF1 gene was more precisely defined. The RF2 gene is located at 62.3 min on the chromosome, while the RF1 gene is located at 26.7 min. This approach to mapping cloned genes promises to be a rapid and simple means for determining the gene order of the genome.
大肠杆菌中蛋白质合成的终止需要两种密码子特异性因子，即RF1和RF2。RF1介导UAA和UAG指导的终止，而RF2介导UAA和UGA指导的终止。编码这些因子的基因已被分离和测序，并且发现RF2由两个独立的阅读框编码。据报道，RF1在大肠杆菌染色体上的图谱位置为27分钟，而RF2的图谱位置尚未确定。在本研究中，使用脉冲场凝胶电泳和跨越整个染色体的有序噬菌体文库这两种新的独立基因定位方法来确定RF2基因的图谱位置。此外，RF1基因的位置得到了更精确的界定。RF2基因位于染色体上的62.3分钟处，而RF1基因位于26.7分钟处。这种克隆基因定位方法有望成为确定基因组基因顺序的一种快速而简单的手段。
